Abstract: Double alkali method for removing arsenic from the leaching residue of the ash generated in the copper smelting electrostatic precipitation（ESP） process was studied.Through the investigation on the single factor conditions，such as leaching agent concentration，leaching time，temperature，and liquid-solid ratio，the optimal process conditions were obtained as follows：concentration of NaOH was 1.1 times of the theoretical amount，liquid-to-solid ratio（mL/g） 4∶1，leaching temperature was 60 ℃，and the leaching time was 2 h.Under these conditions，the arsenic leaching in ESP ash has achieved good results， and the leaching rate was more than 90%.The sodium arsenate′s purity was above 95% by purification.

Key words: copper smelting, electrostatic precipitation, leaching residue, arsenic removing